Abstract

Microseisms are generated by the coupling of ocean waves with the solid earth, and their peak frequencies and source regions vary in different regions. Until recently, there have been few works on microseisms using data recorded in China. Here, we use continuous waveforms from three arrays, that is, W01, W02, and North China Interior Structure Project (NCISP‐8), along the southern coast of China to study the types and source regions of microseisms recorded in south China. Using cross‐correlation functions and the three‐component frequency–wavenumber (fk) analysis, we found that microseisms in this area arrive mainly from the east‐southeast, propagating mainly as surface waves, including both Rayleigh and Love waves. We also found that the Rayleigh waves and Love waves have diverse source regions which are frequency dependent, and have no obvious seasonal changes in source directions. In the 0.2–0.25 Hz frequency band, both the Rayleigh and Love waves at the W01, W02, and NCISP‐8 arrays share common source regions of microseisms located in continental slope around China, whereas in the 0.27–0.5 Hz frequency band, the energy of microseisms are governed by the offshore source regions nearby the stations. In addition, Love waves have a broader range of back azimuths than those of Rayleigh waves at the inland array W01, which may be due to the energy transfer from Rayleigh waves to Love waves in the thick sediment layers during the propagation from the coast to inland.

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